It doesn't require obedience - it requires faith!!
The faith that we are talking about is faith in Him - that means we believe He is their, like in the Great I AM.
Because we believe He is their we seek Him, and just like it is written (all those who seek find) we find Him.
Because we find Him we hear from Him who we find.
Then, since He is Lord of lord, we get instructions from Him, plus a lot more, but instructions.
Then we are faced with the fact that the One who we think is God is giving us instructions, we the things that He says!!
Doing those things results in "obedience!
Therefore faith in Him results in "obedience"!
Of course there is that BIG PROBLEM, which is that we are people!
For numerous reasons, we don't always do what He says, even if we do believe Him and thus hear Him!!!!
So now comes in the "religious spirit" - a demon straight from Satan - which works on our religious pride. So we come across sounding pious. We stop being honest with ourselves. Still, pride is pride whether from a religious spirit or not. Even sarcastic remarks about "Does anyone want to explain the sufficiency of Christ's work in light of the necessity of our obedience?" has obvious "pride in it!
Certainly there is someone who wants to explain it, and if we were seeking Him then we got the explanation, right?
He even explained in in the Scriptures, which He wants to go over with you, right?
James 2:14 What use is it, my brethren, if someone says he has faith but he has no works? Can that faith save him?
James 2:17 Even so faith, if it has no works, is dead, being by itself
So obviously "obedience comes into play!
Yet one person declares it doesn't, proving they don't know Him, and another person declares they don't sin and always do what He tells them, and also proving they don't know Him.
Yet where are the testimonies?????
Jame 2:18 But someone may well say, “You have faith and I have works; show me your faith without the works, and I will show you my faith by my works.”
I have and will show you my faith by my works, but I will also try to be honest and show you my humanity when I heard from Him, My Lord, and didn't do what He told me.
What I find amazing is that He, being God, can and has gotten me to do things (be obedient) in ways that I could never have gotten myself to do by my great efforts - like when He got me to quite a good job to spend all I had to open and run a Christian bookstore for Him and loose it all for His sake. I was obedient, but only because He is great enough to get me to do it. Then He would clearly ask me to do something so easy and simple that I certainly should be able to do it but couldn't get myself to do that - like the time a fantastic look lady came into the isle I was on and the Lord clearly asked me to inquire if she was going to church tomorrow, which happened to be Easter Sunday, but I could get myself to talk to her. Which was even worse after I asked Him for help and He got her to suddenly talk to me about doing a bar-b-que the next day. It would have been so simply to just say something like 'Are you doing that bar-b-que after going to church?' But I could even get myself to respond like that.
The point is: That a day will come that we will declare that we are worthless servants because we only did what He said, knowing that even needed help from Him. Still He will consider us faithful because we believed that He was there and did say things to us, so we did something for Him.
So what about the question: "How can Christ's work be sufficient for our justification when our salvation also requires our obedience?" - well that is bunch of religious non-sense - that's what about the question! Yeah, we are justified by Him, and we get salvation from Him, and faith with obedience too from Him - but if someone is asking do they know Him? If so, why are they asking us? Ask Him, and if you do know Him it will be easy for Him to show you what was going on in your own life!
I should probably be a bit nicer and more understanding. Yet when you read the Bible you find the authors getting a bit done by those religious spirits in people. Look again at what James wrote - was he not a bit upset with those pretending to be pious but clearly not taking things to the Lord - or why did James write what He did?
James 2:20 But are you willing to recognize, you foolish fellow, that faith without works is useless?
Wow, writing "you foolish fellow" is not what I would write, but I might think it.